Spindle and collet for tappet end valves



y 8, 1934. H. c. PRESTON 1,957,848

SPINDLE AND COLLET FOR TAPPET END VALVES Filed Aug. 10, 1932 2 Sheets-Sheet l y 1934. H. c. PRESTON SPINDLE AND COLLET FOR TAPPET END VALVES 2 Sheets-Sheet 2 Filed Aug. 10. 1932 Patented May 8, 1934 UNITED STATES SPINDLE AND COLLET FOR TAPPET END VALVES Henry 0. Preston, Towson, Md: assignor to The Black & Decker Manufacturing Company, Towson, Md, a corporation of Maryland Application August 10, 1932, Serial No. 628,155

4 Claims. (Cl; 279-69) The invention relates to a collet and spindle for valve refacers of the bench or similar types used in the refacing of poppet valves in internal combustion motors and similar valves.

With the type of split collet now in use which is limited as to the variation of its opening to the normal variation in the diameters of the stems of the valves in regular use, it is not possible to accommodate the new type of valve recently brought out by one of the motor vehicle manufacturers in which the valve tappet is omitted and the end of the valve stem is enlarged to take the place of the tappet being approximately one inch in diameter, it being understood that the end of the valve stem thus enlarged is in the operation of the internalcombustion motor in which it occurs engaged directly by the valve cam. With the old type of collet having a limited range of opening and located within the hollow spindle of the refacer, it is impossible to get the lower enlarged end of the valve stem through the collet and still have the collet adapted to so close down as to engage the relatively reduced portion of the valve stem, the diameter of which is approximately in accordance with the previous practice as to poppet valves for internal combustion motors. It is therefore not feasible to clamp the new type of valve in the refacer spindle and to center and align it with any form of collet previously in use. I

In order to provide for the refacing of this type of valve, a new refacer spindle and collet have been devised which can be substituted at the will of the operator for the standard spindle and collet whenever valves of the new type having the tappet formed integrally with the spindle must be treated.

In the accompanying drawings I have illustrated so much of a valve refacer equipped with a. spindle and collet embodying the features of the invention as is necessary to a full understanding of the invention.

In the drawings:

Figure 1 is a fragmentary horizontal section on the axis of the spindle of a valve reiacing machine showing the spindle bearing and a fragment of the grinding wheel, as well as the collet.

Figure 2 is a transverse section on the line 2, 2 in Figure 1.

Figure 3 is a side elevation of the collet showing the two parts slightly separated.

Figure 4 is a view looking from the right in Figure 3 showing the collet open to receive the valve and including a valve which is about to be inserted therein in the direction of the arrow, the valve stem having been severed and the large lower end removed.

Figure 5 is a view corresponding to Figure 1 showing a valve reiacer spindle and including a modified form of collet.

Figure 6 is a view corresponding to Figure 2 including the new form of collet. This view is a section on lines 6, 6 in Figure 5.

Figure 7 is a view looking at the collet from the left as seen in Figure 6, the collet being removed.

Figure 8 is a view corresponding to Figure 4 showing the collet Figures 5, 6 and 7, open to receive the valve and including the valve which is about to be inserted therein in the direction of the arrow.

Referring to the drawings by numerals, each of which is used to indicate the same or similar parts in the different figures, the construction shown includes the spindle bearing 1 of the valve refacer in which is mounted the valve refacer spindle 2 made in accordance with the invention. To the spindle is secured the valve refacer spindle drive pulley 13.

The spindle in accordance with the invention is bored or hollowed out at 3 to receive the large end or tappet end 4 of the valve 5, such enlarged tappet ends being in accordance with the present practice about one inch in diameter. The bore should be such as to provide a neat fit of the large end 4 of the valve stem within the bore 3 of the spindle.

The collet 6 may be of what is referred to as the split type of collet, the two halves 7 and 8 being separated on a plane of the axis. The collet is shown, Figure 4, with the two halves swung open to admit the valve. It consists of a cylindrical inner end portion 9 and a tapered or frusto conical outer end portion 10, which latter taper engages a corresponding inwardly disposed tapered or frusto conical surface 11 at the outer end of the spindle bore 3. The end of the spindle is threaded at 12 on the outside to receive a correspondingly threaded collar 14 which is large enough to pass over the tappet end 4 and has an inwardly disposed flange 15 to engage the outer end surface 16 of the collet, the central aperture 17 of the collet being large enough to admit and clamp valve stems of the regular sizes in automotive practice. The portion of the valve stem to be thus clamped is that above the enlarged tappet end as at 5'. This portion of the valve stem may be described as of normal diameter. Though the diameter of the valve stem at its lower end at 4 is increased, there has been no change in the diameter of the remainder of the stem.

To clamp a valve having a tappet enlargement 4 at the end of the stem, the collet 6 having been first released and removed from the spindle, the enlarged end 4 which fits the bore 3 of the spindle is inserted therein until in the form of spindle shown it contacts the annular positioning shoulder 19 or otherwise until the stem 5' with the head 20 thereon protrudes to the desired extent.

In clamping and aligning a valve the parts of the collet having been first separated as shown in Figure 4 and engaged about the portion of the stem 5 which is of reduced or rather of normal diameter, are passed into the spindle bore, with the valve stem to the position shown in Figure 1. Then the clamping collar 1-4 which has been removed to release the collet, is engaged with the thread 12 and turned down against the collet, the tapered portion of which at 10 is forced into the taper 11 in the spindle, centering the collet and the portion of the valve stem which is engaged therein. The end of the valve stem, i. e., the enlarged or tappet end 4 is centered by the bore 3 with which it has a neat fit as aforesaid.

The grinding wheel in its usual operative relation to the spindle is shown fragmentarily at 18.

The desired adjustment of the refacer having been reached, the spindle and valve are rotated by means of the pulley 13, the valve being held in contact with the wheel 18 which is also rotated until the desired surface obtained or the resurfacing is accomplished in accordance with the usual practice.

Figure 5 shows a spindle and bearing assembly corresponding to Figure l, but it includes a different form of collet 24. This may be made in three or any suitable number of parts 25, 25, 25", divided on an angle corresponding to the number of parts in the collet. For convenience in handling and to prevent loss, the parts of the collet are linked or hinged together by means of U shaped wires or pins 26, the sections of the collet being bored longitudinally, i. e., parallel to the axis at .27 to receive them and the ends which project through the sections of the collet being upset or provided with heads 28 to prevent their withdrawal. The U shaped wires or pins 26, as will be understood, connect two of the sections 25", one of them to each side of the third section 25, leaving an opening 31 between the sections at their unconnected swinging ends 29 through which space and between which ends the valve stem at 5' is inserted.

The hinging of the sections v25, 25', 25" of the collet forming a single integral rnemberdispenses with the necessity for collecting the several sections of the collet when the valve is to be clamped and the hinging of sections turtherserves to position them in their operative relation as they are swung together about the valve stem. Otherwise, the operation of the collet 24 in Figures 5 to 3 is similar to that of collet 6 in Figure 1.

By virtue of the invention the difliculty incident to clamping the improved tappet type of valve in the refacer spindle has seen overcome and means have been provided'whereby the new type of valve having the enlarged tappet end is centered and aligned, centering and aligning the ground surface by centering spaced points on the valve stem. I have thus accomplished with the new type of valve which has hitherto been regarded as presenting insurmountable difiiculties, the same result, or a result of equal merit to that which is obtained with the regular type of poppet valve by means of the centering clamps employed in the previous practice, and without the additional expense which would be involved in the provision of a separate refacer having a larger spindle and larger clamps for this purpose.

I have thus described specifically and in detail a spindle and collet assembly embodying the features of the invention in the preferred form in order that the manner of constructing, applying, operating and using the same may be fully understood, however, the specific terms herein are used descriptively rather than in a limiting sense, the scope of the invention being defined in the claims.

What I claim as new and desire to secure by Letters Patent is:

1. In a valve refacer, means for centering, aligning and clamping a poppet valve having an enlarged tappet end comprising a spindle bored to fit the enlarged end of the valve stem and adapted to position and support said end, a split collet adapted to engage the small diameter of the valve spindle adjacent the head, and means for closing the collet to clamp and center the valve stem near the head, the enlarged tappet end being centered by the bore.

2. In a valve refacer, means for centering, aligning and clamping a poppet valve having an enlarged tappet end comprising a spindle bored to fit the enlarged end, and shouldered to position the end of the stem, a split collet adapted to engage the small diameter of the valve spindle adjacent the head, means for closing the collet whereby the collet serves to clamp and center the valve stem near the head, the enlarged tappet end being centered by the bore, the collet being formed of a plurality of sections, the sections being separated on substantially radial planes, and means pivotally connecting the adjacent sections, an end of one section being free to swing outwardly to admit the Valve.

3. A collet formed in more than two sections ivided on substantially radial planes, links forming a pivotal connection between the adja cent sections, the adjacent ends of two of the sections being free to swing outwardly and admit the Work.

4. A collet for use in combination with the spindle of a valve refacer, the same consisting of a plurality of sections divided radially and normally spaced apart in a circumferential direction as they engage the valve stem, means connecting the sections corriprisine U shaped links, the parallel shanks or the links extending through the collet sections parallel to the axis oi" the collet, the sections being. pivot-ally mounted on said shanks, the sections thus linked being open at one point between two said sections and free to swing outwardly to admit the valve.

HENRY C. PRESTON. 

